What is telephony? Types, benefits and how it works

Telephony is the technology used to transmit voice, text, fax and video communications over distance. In practice, it includes traditional landlines, mobile networks, internet calling and modern business phone systems. Today, most new business telephony uses Internet Protocol (IP) to carry calls over a broadband connection.

Telephony at a glance

• Meaning: technology and services that enable remote voice and multimedia communication.
• Traditional telephony: landline calls carried over copper-based PSTN or ISDN networks.
• Modern telephony: digital calls carried over internet connections using VoIP.
• Business uses: customer calls, internal communication, video meetings, messaging and collaboration.
• UK transition: copper-based analogue services are being replaced by digital alternatives.

What is telephony?

Telephony describes the systems that let people communicate across different locations. Originally, the term referred to telephone calls, but it now covers a wider range of services, including voicemail, conferencing, messaging, video calls and fax.

At its simplest, a telephony system needs a device, a network and a way to connect the people taking part. For example, the device might be a desk phone, smartphone, computer or headset. Meanwhile, the network may be a traditional telephone line, a mobile network or an internet connection.

How does telephony work?

First, telephony captures a person’s voice, converts it into a signal and sends that signal to another device. Traditional telephone systems use electrical or digital signals over dedicated phone infrastructure. Mobile phones use radio signals to connect to nearby masts.

By contrast, internet telephony converts speech into digital data packets. Next, these packets travel across an IP network and are reassembled into audio for the recipient. This is the principle behind Voice over Internet Protocol, usually shortened to VoIP.

What are the main types of telephony?

Traditional landline telephony

For example, traditional fixed-line calls use the Public Switched Telephone Network (PSTN). Older business systems may also use ISDN, which carries digital voice and data over telephone lines.

Even so, these networks served businesses for decades, but UK providers are moving customers to digital alternatives. Openreach explains how the UK is upgrading to digital phone lines. Businesses should identify any phones, alarms, payment terminals, lift lines or other services that still depend on an analogue connection.

On-premises PBX

Meanwhile, a Private Branch Exchange, or PBX, connects extensions within an organisation and manages external calls. An on-premises PBX is physical equipment installed at the business location.

However, this approach can offer direct control, but it requires space, maintenance and technical expertise. Adding users or supporting multiple sites may also require extra hardware and configuration.

VoIP telephony

VoIP telephony uses an internet connection to make and receive calls. The system converts speech into digital packets, sends them across the network and reconstructs them at the other end.

For example, people can use IP desk phones, computers, headsets or mobile apps. Because the service is not tied to one copper line, VoIP can support remote working, multiple locations and flexible call routing.

Hosted or cloud telephony

A hosted phone system is managed in the cloud by a communications provider rather than on equipment kept at the customer’s premises. In turn, the provider maintains the core platform, security and software updates.

As a result, users connect through the internet, making it easier to add extensions, deploy new features and support colleagues in different locations. However, the business still needs reliable connectivity and suitable devices.

Mobile telephony

Similarly, mobile telephony carries calls and data over cellular networks. A smartphone communicates with a nearby mast using radio signals, and the mobile network routes the call or message to its destination.

In addition, mobile services can operate independently or integrate with a business phone platform. With a business calling app, colleagues can make and receive work calls using the company number while away from the office. For wider context, the original article referenced Statista’s smartphone user dataset.

Internet calling and collaboration apps

For instance, applications such as Microsoft Teams, Zoom and WhatsApp use internet telephony for voice and video calls. Many also include messaging, screen sharing and file collaboration. Over time, the shift towards app-based communication has developed over many years, as this BBC report on changing calling habits illustrates.

Even so, consumer calling apps are useful for informal communication, while business platforms typically add administration, number management, call queues, reporting and customer-service features.

Why do businesses use telephony?

Ultimately, businesses use telephony to connect customers, colleagues, suppliers and partners. Therefore, a well-designed system helps calls reach the right person, supports work across different locations and creates a consistent experience for callers.

For example, modern business telephony can combine:

• inbound and outbound voice calls;
• business numbers and extensions;
• auto-attendants and call queues;
• voicemail and voicemail-to-email;
• call forwarding, transferring and parking;
• call recording and reporting;
• video meetings and instant messaging; and
• desktop and mobile applications.

What are the benefits of VoIP telephony?

Flexible working

For instance, colleagues can access business calling features through compatible desk phones, computers and mobile devices. Consequently, this helps office-based, hybrid and remote teams use the same numbers and call-handling processes.

Scalability

Likewise, cloud systems can usually add or remove users without installing a new physical phone line for every person. As a result, businesses can respond more easily to growth, seasonal demand or organisational change.

Connected locations

Furthermore, a single system can connect different branches, workshops and home workers. Calls can move between users without customers needing to dial another public number.

Useful call-management features

Depending on the service, VoIP platforms may include auto-attendants, queues, call recording, analytics and integrations with customer-management software. Of course, available features depend on the provider and package.

Less on-site infrastructure

Finally, hosted telephony reduces the need to maintain a traditional PBX at the business premises. The provider manages the central platform, although customers remain responsible for suitable connectivity, devices and local network performance.

What is unified communications?

In comparison, unified communications brings several channels into one platform. Instead of using separate tools for calls, messaging and meetings, colleagues can access them through a connected application.

A unified communications service may combine:

• voice and video calls;
• instant messaging;
• presence information showing whether colleagues are available;
• screen and file sharing;
• voicemail; and
• contact-centre or customer-service tools.

Overall, this approach can reduce app switching and make it easier for teams to communicate consistently across locations.

What does a business need for VoIP telephony?

Naturally, the precise requirements depend on the provider and number of users, but most businesses need:

• A reliable internet connection: sufficient bandwidth and stable performance for simultaneous calls.
• A suitable local network: correctly configured routers, switches and Wi-Fi where wireless devices are used.
• Compatible devices: IP desk phones, computers, headsets or smartphones.
• A VoIP service: business numbers, licences, call plans and required features.
• Continuity planning: a process for power cuts, broadband failures and emergency calling.
• A migration plan: checks for alarms, door-entry systems, payment terminals or other equipment connected to legacy lines.

Is VoIP the same as telephony?

No. Put simply, telephony is the broad category covering technologies used for calls and related communication. VoIP is one type of telephony that sends calls over IP networks.

In practice, business conversations, “modern telephony” often refers to VoIP or cloud phone systems because these platforms are replacing many traditional fixed-line services.

What is the difference between VoIP and a landline?

In contrast, a traditional landline uses dedicated telephone infrastructure, while VoIP carries calls as data over an internet connection. As a result, VoIP is generally easier to extend across multiple locations and devices, but its performance depends on power, connectivity and network configuration.

On the other hand, landline equipment may continue to work during a local power cut, depending on the service and handset. By contrast, VoIP needs power for the router and other equipment, so businesses should plan a suitable backup.

How should a business choose a telephony system?

First, consider how colleagues and customers communicate. Consider the number of users and locations, remote-working needs, expected call volumes, required integrations and any analogue devices that must be migrated.

Then, ask potential providers about call quality, support, number porting, security, service continuity, contract terms and future scalability. A good solution should fit the organisation’s working practices rather than adding unnecessary complexity.

Telephony FAQs

Does telephony only mean phone calls?

No. Modern telephony can include voice calls, video, voicemail, messaging, conferencing and other forms of communication carried across fixed, mobile or internet networks.

Can a business keep its existing phone numbers when moving to VoIP?

Usually, providers can port existing numbers to a VoIP service. Confirm which numbers are portable, how long the transfer may take and how calls will work during the changeover.

Does VoIP work during a broadband outage?

However, VoIP needs an internet connection. Therefore, businesses can improve resilience with mobile failover, a backup fixed connection, call diversion and suitable power protection.

Is cloud telephony secure?

Yes, provided the service and local network use appropriate security. In particular, ask about encryption, account controls, fraud monitoring, software updates and how the provider handles data.

How can Wayv help?

Wayv provides business phone systems designed around the needs of UK organisations. If you need to replace legacy lines, support flexible working or bring several locations together, talk to our team about your requirements.